Be sure that your pine trees are not kept indoors for too long. These trees require many hours of bright light, which is why they do best outdoors. If used indoors, keep it near a window that receives ample bright light or in a location that gets many hours of light. Allow the soil to dry out slightly before watering, and then soak the soil until saturated once it is dry. Do not allow excess water to sit in the pot if the soil is saturated.